A novel asymmetrical tri-tert-butyl naphthalocyanine was prepared for the first time by the condensation method and by the use of structurally distorted subnaphthalocyanine. respectively. Thr advantages of the latter ...A novel asymmetrical tri-tert-butyl naphthalocyanine was prepared for the first time by the condensation method and by the use of structurally distorted subnaphthalocyanine. respectively. Thr advantages of the latter method were more convenient purification and relatively higher yield.展开更多
Adsorption behavior of Fe atoms on a metal-free naphthalocyanine(H2Nc) monolayer on Ag(111) surface at room temperature has been investigated using scanning tunneling microscopy combined with density functional th...Adsorption behavior of Fe atoms on a metal-free naphthalocyanine(H2Nc) monolayer on Ag(111) surface at room temperature has been investigated using scanning tunneling microscopy combined with density functional theory(DFT)based calculations. We found that the Fe atoms were adsorbed on the centers of H2Nc molecules and formed Fe–H2Nc complexes at low coverage. DFT calculations show that Fe sited in the center of the molecule is the most stable configuration, in good agreement with the experimental observations. After an Fe–H2Nc complex monolayer was formed, the extra Fe atoms self-assembled to Fe clusters of uniform size and adsorbed dispersively at the interstitial positions of Fe–H2Nc complex monolayer. Therefore, the H2Nc monolayer grown on Ag(111) could be a good template to grow dispersed magnetic metal atoms and clusters at room temperature for further investigation of their magnetism-related properties.展开更多
Cyclic-conjugated linkages between planar-macrocydic molecules contribute to the robustness of the two-dimensional (2D) polymerization and extension of π-interactions. The fabrication of such linkages in 2D polymers ...Cyclic-conjugated linkages between planar-macrocydic molecules contribute to the robustness of the two-dimensional (2D) polymerization and extension of π-interactions. The fabrication of such linkages in 2D polymers remains challenging. Combining scanning tunneling microscope (STM) measurements and density functional theory (DFT) calculations, we demonstrate a linear polymerization of metal-free naphthalocyanine (NPc) molecules with [4]-radialene-like linkages on silver surfaces. Experimentally, by depositing NPc molecules on the Ag(110) surface and subsequent annealing up to 750 K, one-dimensional polymers are constructed along the [\(1\overline 1 0\)] direction. High-resolution STM images show a stem-leaf-like feature. STM simulations based on a linear polymer of NPc molecules linked by four-membered carbon rings, [4]-radialene-like structure, agree well with the experimental observations. DFT calculations reveal that the polymerization process includes detaching two-terminal H atoms of NPc molecules along [\(1\overline 1 0\)] direction, then bonding with a neighboring dehydrogenated NPc molecule by forming a four-membered ring. The dehydrogenation process can be promoted by on-surface impurities such as additional H atoms. Similar polymerizations have been achieved on Ag(111) surfaces in an amorphous way. Moreover, the energy gap of the NPc molecule decreases after linear polymerization, suggesting a red-shift for its optical absorption/scattering spectrum. Our study offers a new route to polymerize conjugated molecules with extended planar π-interactions.展开更多
文摘A novel asymmetrical tri-tert-butyl naphthalocyanine was prepared for the first time by the condensation method and by the use of structurally distorted subnaphthalocyanine. respectively. Thr advantages of the latter method were more convenient purification and relatively higher yield.
基金supported by the National Natural Science Foundation of China(Grant Nos.61390501,51325204,and 11204361)the National Basic Research Program of China(Grant Nos.2011CB808401 and 2011CB921702)+1 种基金the National Key Scientific Instrument and Equipment Development Project of China(Grant No.2013YQ1203451)the National Supercomputing Center in Tianjin,China,and the Chinese Academy of Sciences
文摘Adsorption behavior of Fe atoms on a metal-free naphthalocyanine(H2Nc) monolayer on Ag(111) surface at room temperature has been investigated using scanning tunneling microscopy combined with density functional theory(DFT)based calculations. We found that the Fe atoms were adsorbed on the centers of H2Nc molecules and formed Fe–H2Nc complexes at low coverage. DFT calculations show that Fe sited in the center of the molecule is the most stable configuration, in good agreement with the experimental observations. After an Fe–H2Nc complex monolayer was formed, the extra Fe atoms self-assembled to Fe clusters of uniform size and adsorbed dispersively at the interstitial positions of Fe–H2Nc complex monolayer. Therefore, the H2Nc monolayer grown on Ag(111) could be a good template to grow dispersed magnetic metal atoms and clusters at room temperature for further investigation of their magnetism-related properties.
基金This work was financially supported by the National Key Research and Development Program of China(No.2016YFA0202300)the National Natural Science Foundation of China(Nos.61888102 and 61725107)+2 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB30000000)the International Partnership Program of Chinese Academy of Sciences(No.112111KYSB20160061)China Postdoctoral Science Foundation(No.2018M641511).
文摘Cyclic-conjugated linkages between planar-macrocydic molecules contribute to the robustness of the two-dimensional (2D) polymerization and extension of π-interactions. The fabrication of such linkages in 2D polymers remains challenging. Combining scanning tunneling microscope (STM) measurements and density functional theory (DFT) calculations, we demonstrate a linear polymerization of metal-free naphthalocyanine (NPc) molecules with [4]-radialene-like linkages on silver surfaces. Experimentally, by depositing NPc molecules on the Ag(110) surface and subsequent annealing up to 750 K, one-dimensional polymers are constructed along the [\(1\overline 1 0\)] direction. High-resolution STM images show a stem-leaf-like feature. STM simulations based on a linear polymer of NPc molecules linked by four-membered carbon rings, [4]-radialene-like structure, agree well with the experimental observations. DFT calculations reveal that the polymerization process includes detaching two-terminal H atoms of NPc molecules along [\(1\overline 1 0\)] direction, then bonding with a neighboring dehydrogenated NPc molecule by forming a four-membered ring. The dehydrogenation process can be promoted by on-surface impurities such as additional H atoms. Similar polymerizations have been achieved on Ag(111) surfaces in an amorphous way. Moreover, the energy gap of the NPc molecule decreases after linear polymerization, suggesting a red-shift for its optical absorption/scattering spectrum. Our study offers a new route to polymerize conjugated molecules with extended planar π-interactions.